Step 1 Rinse the anchovies under running water to remove excess salt and then soak in water to cover in small bowl until softened, about 5 minutes. Remove the fillets, discard the skeletons and soak another 5 minutes until flexible. Chop coarsely.
Step 2 With a mortar and pestle, pound the garlic with the salt to a smooth paste. Add the capers and chopped anchovy, and pound to a coarse paste. Add the herbs and pound to a paste. Starting with just a little at a time, add the olive oil, stirring with the pestle to make a smooth emulsion. Stir in the red wine vinegar. Taste and adjust salt and vinegar.
Step 3To make salsa verde in the blender or food processor, pulse the anchovies, garlic, capers and herbs to a coarse paste. With the machine running, slowly stream in the olive oil. Stir in the vinegar and add salt to taste.